It was so sad when Todd killed Andrea. I think that was just the nail in the coffin for Jesse. He already had some serious issues with guilt. Then Walt goes and tells him he watched Jane die, and then he has ANOTHER girlfriend die because of him. This is it. There was some chance before that he might have been able to get out, get some therapy and go on to live a "normal" life. No chance now. I'm so sad, Jesse is by far my favorite character.